CAMP FOSTER, Okinawa — Okinawa Gov. Takeshi Onaga is stepping up efforts to block a controversial U.S. military runway being built in northern Okinawa after a breakdown in negotiations with the Japanese government.

According to Japanese media reports, Onaga is expected to revoke the landfill permit for the runway, which was approved by predecessor Hirokazu Nakaima, by Sept. 19. Nakaima OK’d the plan in exchange for billions in subsidies for Japan’s poorest prefecture.

The runway would facilitate closing and moving flight operations from Marine Corps Air Station Futenma, located in a densely populated urban area in central Okinawa, to Camp Schwab in the island’s remote north.

It remains unclear if Onaga has a legal basis for revoking the permit. Scholars have said the issue will likely be decided in court.

Onaga also plans to speak about his case to the U.N. Human Rights Council in Geneva on Sept. 21 and 22. He also has floated the idea of a prefectural referendum, which could put further pressure on the Japanese government to halt construction of the Camp Schwab runway into Oura Bay at Henoko.

“I think the public will in Okinawa was already shown in a series of elections last year but [the government of Japan] does not want to acknowledge that,” Onaga was quoted as telling reporters, referring to his overwhelming victory in November and the Dec. 14 Lower House elections, which were swept by candidates opposed to the relocation.

The Japanese and American governments have said there is no viable alternative.